Methane T-Dwarf Candidates in the Star Forming Region IC 348

Abstract

IC 348 is a young (t$\sim$3Myr) and nearby (d$\sim$340pc) star forming region in the Perseus molecular cloud. We performed a deep imaging survey using the MEGACAM (z-band) and WIRCAM (JHK and narrowband CH${_4}$ on/off) wide-field cameras on the Canada-France-Hawaii Telescope. From the analysis of the narrowband CH${_4}$ on/off deep images, we report 4 T-dwarf candidates, of which 3 clearly lie within the limits of the IC 348 cluster. An upper limit on the extinction was estimated for each candidate from colour-magnitude diagrams, and found consistent with extinction maps of the cloud. Initial comparisons with T-dwarf spectral models suggest these candidates have a spectral type between T3 and T5, and perhaps later, potentially making these among the lowest mass isolated objects detected in a young star forming region so far.